A majority of deaths following burn injury can be directly attributed to the patient's inability to muster sufficient defenses against infection, despite the availability of a vast array of therapeutic agents and techniques. Clearly, we need a better understanding of why normal immune mechanisms fail. This proposal addresses three specific problems, carefully selected to provide a more lucid understanding of host immune function following thermal injury: First, we plan the collection and evaluation of comprehensive data concerning the immune competence of burn victims. This would include a continuous monitoring throughout the burn recovery period of the following: serum proteins (including immunoglobulins, CH50, C'lq, and C'3), peripheral blood B- and T-lymphocytes, mitogen transformation of lymphocytes, analysis of neutrophil function, and detection of auto-antibodies. Second, we intend to study the mechanisms by which biologic membranes facilitate wound closure, and determine whether the immune consequences of porcine xenograft application act with uniform benefit or occasional detriment to the patient's welfare. Third, we propose to collect and test patient serum for immunosuppressive activity in vitro and in vivo. Specific immunosuppressive serum proteins will be identified by two-dimensional electroimmunodiffusion, and specific antisera raised and tested for their ability to cancel immunosuppression. It is our ultimate goal in each of these studies to identify host responses which might be manipulated to the patient's advantage.